The 657M Actuator is used for the automatic operation of control valves, and is designed as a direct acting, spring-opposed diaphragm. By varying the pneumatic loading pressure on the actuator diaphragm, the valve plug within the body will open, close or throttle.
Features- The valve plug action of the 657M Actuator can be set to “push down to close” or “push down to open” and will then either open or close the control valve upon failure of the loading pressure.
- When the loading pressure fails, the diaphragm of the actuator moves to the extreme upward position and performs the selected action.